The REAL Answer Explained

Media outlets around the world went crazy over a 5th grade math exam question in China. But they all missed the real story! The problem actually dates back to French researchers in 1979. In this video I present the real story to the viral "Chinese" captain's age question.

The REAL Answer To The Viral Chinese Math Problem "How Old Is The Captain?"

Update thanks to comment from Markus Schüt: the origin dates back to 1841 in a letter Flaubert wrote! See:

My blog post for this video:

Captain's age question
"If a ship had 26 sheep and 10 goats onboard, how old is the ship's captain?"

South China Morning Post

The Portal (Chinese)

RT

BBC

Washington Post

Newsweek

Official response (Chinese).

Sherlock Holmes' deduction in The Hound of the Baskervilles

Novotná, Jarmila, and Bernard Sarrazy. "Model of a professor’s didactical action in mathematics education: professor’s variability and students’ algorithmic flexibility in solving arithmetical problems." The Fourth Congress of the European Society in Mathematics Education. 2005.

de Corte, Eric, Brian Greer, and Lieven Verschaffel, eds. Making Sense of Word Problems. CRC Press, 2000. Pages 3-5.

Reusser, Kurt. "Problem solving beyond the logic of things: Contextual effects on understanding and solving word problems." Instructional Science. 17.4 (1988): 309-338.

Benjamin Dickman Twitter and tweet

Benjamin Dickman answer on Math Educators Stack Exchange

Gene Wirchenko blog

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[MindYourDecisions]

The entire worldwide media missed the actual history of this problem! Please tweet this at any news organization that posted a story so they can share the real story dating back to French researchers in 1979.


Also, some minor clarifications/corrections and one elaboration:

3:06 - A more accurate description is: Benjamin Dickman, who has a Ph.D. in Mathematics Education from Teachers College, Columbia University, and currently teaches math at The Hewitt School, an all girls day school in New York City. Benjamin believes such problems are well-known to math education researchers, specifically those with interests in sense-making, problem solving, and problem posing.

5:02 - the blog "has other posts, too"


"Mathematical tools have requirements for their use. For example, if one has two of voltage, current, and resistance for some types of electrical circuits, one can compute the third using the formula E=IR. BUT you must have two of the values. If you only have one of them, you do not have enough information.

"In a real world problem, you may have to hunt down the missing information. Sometimes, you can compute a missing value from other information given in the problem.

"For example, in the problem 'Albert has 25 marbles more than Carl does. Beth has 45 marbles. Carl has 15 fewer marbles than Beth. How many marbles does Albert have?', Albert has c + 25 marbles. We do not know the value of c, but we do know that c = b - 15. That still is not enough, but since we know b = 45, we can substitute 45 for b to get c = 45 - 15 = 30 and then for c in a = c + 25 to get a = 30 + 25 = 55. Thus, Albert has 55 marbles."

[Alex-dror]

Luke has 5 apples, he gives 3 apples to John.
Calculate the mass of the Sun.

[বিজ্ঞানপত্রিকা]

A school inspector visited a class and asked the students, "If the price of a dozen of bananas is 10 dollars, then what is my age?" One of the students promptly answered ''50". "That's correct", the inspector replied delightedly, 'but how could you figure that out so quickly?' The student said, 'we have a neighbor of age 25, who is half-mad. But you are completely mad, so it must be 50.'

[somsnosa]

I was asked this question as a kid, but there was a different spin to it. It was worded: "Imagine, on YOUR ship there are...", and then had a long list of random stuff found on the ship to make the student forget the crucial information from the very beginning: that THEY are the captain, so the correct answer is their own age :)

[queenv]

Bill is an engineer. He has been married for 20 years and has 2 daughters. He is professionally successful and his family love him. Find the age of the guy Bill's neighbour met on his trip to Italy.

[juliard]

its always "how old is the Captain?" but never "how is the Captain?"

[jesselapides]

nobody said the captain was *legally* driving the boat

[Sir_Aurelius]

My exact thoughts after reading it: “old enough to be a captain”. 🤷‍♂️😂

[amirhassan]

"Old enough" was my 1st answer

[abdelilahsalimchatar]

A triangle has 3 angles. Calculate the moon’s distance from Earth.

[rudiralla]

A Mother is 21 years older than her child. In 6 years she's 5 times as old as her child. Where is the father?

[snperkiller]

As many have pointed out, the main issue is that "this is unsolvable" or other variation of that answer get severely punished by a lot of teachers even if it is the correct answer and not just in primary school, i can personally remember two instances in high school, one of them being in final year on a physics class exam where with the parameters given the problem violated the laws of physics and i got failed that exam for pointing that out, even with the teacher admitting that there was indeed an error in the problem.

Most mandatory education seems hell bent to kill any sense of logic or inquisitiveness in students.

[nxpy]

Assume the captain's age is 69 year's old.
Therefore his age is 69 . Hence, proved.

[peterphillips]

Watching this felt like a Zoom meeting that could have been an email

[abiseniyya]

Easy.
The captain is 42 years old.
How do I know?
He's my cousin.

[ronaldcharlton]

My daughter was set an on- line exam (timed), when applying for an accountants job. She was working through the questions well but running out of time to complete the full set and was beginning to panic. Then she stopped finished the final question she could answer in the time and noted at the end " I have not completed the final questions as they would have been guesses and you do not hire an accountant to make guesses" . She got the job.

[yoursleepparalysisdemon]

It’s because when we are given a question schools teach “there’s always an answer”.

This is the result.

[jimclark]

He's one day older today than he was yesterday

[prakharmishra]

2+2=4. Calculate how many stars are in the milky way.

[allenhonaker]

As long as this question is framed as a math question people will try to get a mathematical answer. The real question should be how to get people to change their frame of reference and what should be the basis of their doing so